Automatic screw machine



Original Filed Oct. 11, 1941 F. G. SILVA AUTOMATIC SCREW MACHINE 6 Sheets-Sheet l www ' yf- ATTORNEY Dec. 5, 1944.

F. G. slLvA 2,364,169

AUTOMATI C S CREW MACHINE Original Filed OC'C. 11. 1941 6 Sheets-Sheet 2 Dec. 5, 1944. F. G. slLvA AUTOMATIC SCREW MACHINE original Filed oci. 11, 1941 Sheets-sheet s DCC 5 1944- F. G. slLvA AUTOMATIC SCREW MACHINE original Filed oci. 11, 194i 6 Sheets-Sheet 4 Deco 5, F'I G. AUTOMATIC SCREW MACHINE Original Filed OCT.. ll, 1941 6 Sheets-Sheet 5 Dec. 5, 1944. F. G. slLvA 2,364,159

AUTOMATIC SCREW MACHINE original Fi1ed ont. 11, 1941 e sheets-sheet e description.

turret between successive cutting operations,f

comprises, preferably, a 'rapidly operating crank tion to engage the bar 33. The disk shaft 5l and rod device, the rod being further actuated Y Y' by cam means, while the slide is advanced, foiI v eifecting the feeding movementof the turret for .l

cutting yoperation of the tools.l Thef.crank is shown at 26 (Fig. 3) on the shaft 21 rotated in `bearings on the' slide by means hereafter described, the rod being shownlat 23..,ashat'lnga'v rotary connection at one e'n'dwith the crank. j

will be moved rearwardly into engagement with the corresponding actuator 34 selected as de- The other end of the yconnecting rod is connected with and actuated by a lead cam shaft mechanism, which forms no vpart of the `present invention and needsh'only4 the followingbrief Fixed on the` main ,framef is a shaft l29 on whicha hub 36 is mounted vfor rocking movement. Extending integrally from the hub is an ar1n3l `with which the rod,r 28 is connected.

yOther integral arms 32 carry a cylindrical bar ,abutment arranged for engagement with an adjustable stop part 36v on the frame, for limiting the movement ofthe hub in the kforward direction,` and it will beseen that as thev slide crank 26 is ,rotated through 180?, itsconnecting rod is indexed, by any known or suitable mechanism, in timed relation withthe indexing of the turret, so that as each toolis brought to operating position, one of the actuators 34 isbrought to lposition to engage bar 33 for rocking the hub 36 and feeding` the tool to cutthe work under control of the particular cam corresponding to vsuch tool and the particular portion of the rise of the cam `required to effect the cutting action. A spring actuated plunger 52 normally holds each bellcrank lever 46 against a stop 53 on the frame, v,exceptas the lever may be held above the stop by its 4corresponding cam 31. It will be apparent from .the above description that as crank26 is rotated through 180 to retract the slide, and the turret is indexed and the crank is again rotated to advance the slide, bar 33 scribed, ,th,us establishing a positive connec- Vtion between'one of thecar'ns 31 and the turret and the selected camthen advances thetool to 28 rocks hub 36funtil stopped by its abutmentY 3 5, at the same timeV rapidly retracting thel turret slide, said mechanism affording a positive Withdrawal of the turret r,and-its tool toa position in which the turret maygbe :indexed by, suitable,

,cam shaft 38,as fully described inisaid; applicat. `tionySerial No. 386,130.-I Each V,cam `engages a roller 39 on a corresponding lever 40, one for each cam, each .of such levers being pivoted at 4I Yon the mainframe androcked in accordance with the shape and proportionszof its corresponding cam. Lever v4l) is formed `with a ,.slotted, arcuate` `surface d2 on which a block 43 isslidably adjustable to `varythe amplitudeof `throw of the cam. {Pivoted to each block is a rod 44' which has pivotedA thereto, atfa vlongi-L tudinally adjustablev point, 'onearm 45, of 1a, bell crank'lever 46 pivote'd at 41 onr the frame. The other arm 48 of each of vthe leversi46 is pivotally connected lwith one'of the actuators 34, which y.latter are `normally depressed by springs 49into engagement with a controlling disk `assembly indicated generally at 5l) on a shaft 5|. 4; f

lThe `disk assembly 56 serves to. connect the lead cams and their respectiveY actuators 34, .individually and; selectively, with-the turret slide,

to rapidly control the feedingv actuation of the various tools in` succession byconnection with allows the actuatorend to drop down into posiperform theV cutting operation. By suitably timing the indexing of. the turret and the selecting disks for the actuators, the tools may be rapidly operated, `one after anothenbythe useful rising portionsonly of the respective cams.

The means for intermittently rotating crank 26 f for reciprocating the turret slidel comprises, preferably, an angular gear54 fixed on vthe crank vshaft v21 and mating with a gear 55 fixed' on a shaft 56. The Ashaft has xedthereon` a spur gear 51 meshing With an felongated spur gear 53 fixed on a, shaft 59 and driven iby a geared connection with the main orhand wheel-shaft 66 of the machine.

' 'I'he means for indexing the turret comprises, preferably, a spur 6I on gear 54 coacting with a series of 'radial slo-ts formed in an index wheel 62 fixed on the turret shaft. Spur 6|, rotating with the crank 26, cooperates With the index Wheel to index the turret the usual fashion.

The means for indexing the disk assembly 50 from toolI to tool `in for selecting the actuators 34 comfprises,`prefer ably, an angular gear 63' fixed on `shaft 59 and mating with a gear 64 which carries ya spur 65 .cooperating with an index wheel 66' fixed on the .shaft 5I of the'selector disk assembly. Thefdetimed relation with eachother. Suitable-devices f aregprovided for cushioning the Vmotions ofthe turret slide and centering the turret and selector assembly in' their index positions, butsuchv devices form no part of the present invention? S- .The cross slide mechanism comp-rises,.. preferably, a frontv slide 61 (Figs. 3 and 6) :anda rear slide 68 (Figs. 1 and 6). These slides=are adapted to carry .tools-of the usual. character, as indicatedat 6,9, 10,. and Slide in ways 1i andiz, respectively, on Opposite sides of the machine frame. A spring 13 (Fig. 6): housed in 'arbore in Veach slide,` presses at oneL end` 14 against a'stop 15 on the frame to aid in retracting theslide. i

The `means forpositively actuating the.l cross slidespreferablyr comprises a `lug 16 on. the top of .each Vslide toy,whichis pivotally yconnected 5.a

[orilla cross slide camshaft |04.`

ushown.` Lever lllluis pivoted` onthe frame atl ,181| and carries a stop pin 82 arranged to `engage. an

abutment 83 on timeframe, vto limitthe outward the same foreach of the icross slidest movement of the. slide, Ythe .i above fiparts being ,Means are provided forrapidly actuatingleach cross lslide lever 80, ,in conjunction;` With-cam one; endto the slide lever 80. The links of eacli i jpairhave apivotal knee` connection` with each i .othenat 85, at which pointI a means, hereafter described, is alsogconnected forrapidlystraightr y ening ,and breaking the ytoggle `movement oftheslide,` l l 4 i i The `cam actuated means` for `effecting the `feeding movement not `thetvvo cross slides are substantially the!sainz-:n4 The rear -slide 68 has the opposite end of `:itspair of toggleilinks pivoted at A8|fto one arm of a bellqcrank lever 81 provided `witl1a,:.si ',op pin.88 positioned forlcontact with a frame abutment B9 i. to jlimit the `retracting lI novernent, of the lever. {The v,opposite arm of the lever is pivo-tally connectedat 9,0 with alink 9|,

i having any known o r suitable means, such as `the @threaded joint indicated `at. 92, v`for adjustingits `length.-` The oppositemendof link 9|;Yis pivoted at;93to one arm of abell crank'lever 34 pivoted if on the frameat 95 and having its other armpiv? `otedat 96 `to a link 91" which. is lpivotally con- `nected with a block-98` sliding in a T-slot confnection With the arcuate surface 99 l of` `a lever a, lllrpivoted on theframe` at IIlI and carrying a The ,front cross slide ,61 `liaiitsL toggle Ievifs @iw-tally permette@ at ,|05 withalever |06 pir- Aote'dtonthe;irameat 8 5. Pivotedl ltothelever l'I'Olisa link -[IllY pivotally connected with 1a block |08 `having aslidably adju-stable T-slotconnec (tion With an arcuatejbearing surface on a` lever 109` having a roller llllbearing `on aicam on shaft |04 (Fig. 3)., as inthe caseiof the opposite slide. By selecting suitable cams,adjusting the blocks 98 and |08 on `the cenit-levers to control their `effective throw and adjusting `the lengths of `the `links ll, the feeding actionof the cross slides is precisely controlled inkpositioln and amg nitide t 1. y i p Y lIhe-means `forstraightening andlbreaking the -toggles of thegcross slidescomprises Vaqpairiof `links `I I2 andl I3 (.Fig. 6) respectively, provided `vvithany known or suitable means,` such as the l 4threaded joints indicated generally jat |,I4` `and |`I5, respectively, `for `adjusting their lengths. @ne end of each link islpivotally engaged with the knee section 85 of'the correspondingtoggle, l

llThe opposite ends of the links are pivotally conmeans forr producing the feedingl actuation for ,cutting the Work. `Such meanscomprisesypreie1jab1y,]a pair lottoggle leversill` for each slide (Fig. f6), one leverfof eachpair being pivoted :at

to I effect; `quiek` sections, comprising the rognes, give to the slides 'thefurther feeding motion `required for :the tie-- sired cutting operation on the Work, in a rapid` and.;` precisely controlled manner. As will be noted, the cross slide mechanism is relatively sim 4ple and strong in construction and is` compactly @The mechanism for driving the several parts of the machineiin timed coordination with one another comprises, preferably, the saidmain or vhand Wheel shaft 60 preferably driveniby an electric motor (notshown) within the mainframe'.

Asprocket chain I 24 (Fig. `2) leads from a sprock- A etwheel `rotated by said motor to a. sprocket wheel '|25 fixed on a hub |126 riding idly on the shaft and `having a lateral clutch face |21. `Splined on `the shaft is `a `hub I 28 having a cooperating clutch face (|29` for clutching the sprocketito the` shaft .to drive the shaft.`

`A handle |30 (Fig, 5) conveniently accessible at the lefthand end of the machine, has a forked .end |3| (Fig. 25 for shiftingtheiclutch part |29 `to control the rotation of the driven shaft. lThis shaft,Y at the opposite 'endof themachine, is equipped with the usual handwheel |32 by means of which it may be, rotated for setting up and adjusting the machine.` This main `shaft 60 car ries the several `clutchiunits for controlling `the l successive `rnovementsof `the horizontal turret,

the` turretiand `cross slides, andthe devices for operating `the workspindlesuch clutch units befV q ing `operated `by trip levers actuated "by dogs` mounted on carrier `Wheels fixed on theycross slide cam shaftextending along the front side of the machine, which `vvill now be described.

Fixed `on theymain `shaft adjacent thehand Wheel is a gear `|33 (Fig. 1) Whichdrives a train of change speed gears, indicated generally at |34,

nected at I I8 and` l I'I,` respectively, with cranks insana Hering. 1)` ongearsizaanu 12|, 1e- -spectively l vvliich mate with gears i |22 and |23,

which latter areintermittently clutched tol the ,main shaft 60, by means hereafter described;I ffjBy the above described. means, comprising` `the of` the usual or any suitablevariety, as well underi stobduintheart, and forming nopart `of the posite end of shaft |36, adjacent theleft hand end of the machinedFig. 2) has fixed thereon a bevel gear |39 mating Withwagear` |40 xedjon a shaft |4| (Fig. 5), `which, extends `acrosslthe.

endof the machine to theifrontside, where it drivesa Worm `gear |42 meshing with a worm Wheel |43 iixed on the said cross slidecamshaft |04 extending alongthe frontside of` the ma.- jchinei i l The i cross slide camshaft has xed thereon a series of wheels or carriers `on which are mounted the dogs for tripping a series Aof pivoted `triple-` yers,.extending across to the'` rear` side of the", machine and provided at their oppositeor `rear ends with means for lactuating theseveral` clutches referred to above, as best shovvnin Figs.

said shaft `|I'I4 is aitrip` `dog carrier |44 for conl- @Oggles are straightened to rapidly :advance the nrQSS.,S1ideS. and, ashev` are .straiglite,ned.:` the j @m5 .LU l. andi..lllithroushgtheir descrbedlcon;

scription of which will applyl to the crossslide and other carriersofthe `series on the shaft` Carrier |44 is a Wheel formed in `one side face `with a `T slot |45 (Figs. 3 and 6l, havinganfentrance at" |46, andinlwhich are -anchored the bol'S. VMillor, clamping onf eacharrierfoneor more trip dogs |48. Eachdog 'is thus adjus'tably bolted Ion anydesired point on the periphery of the carrier, which may be marked with an appropriate scale (not shown) for so positioning the dog. Each dog has a cam-shaped projection |49 for engaging and lifting a cam-shaped nger |50'lxed adjacent the end of a corresponding trip lever Carrier |44, which controls the motion of the horizontal turretslide and its indexing mechanisms, is provided with a plurality of dogs, corresponding to the plurality of tools, as indicated in Fig. 6. This carrier is constructed, therefore, to receive such dogs on each of its opposite faces,

4for cooperation with a pair of trip lingers |50,

one on each side of the lever, which facilitates .the convenient adjustment of the dogs in any desired location on the carrier. The opposite end of rtrip lever |5| is broken away in Fig. 6 but is shown in Fig. '1 adjacent Fig. 6, as carrying an abutment in the form of a stud or spur tooth |52 engaging in a slot |53 formed circumferentially in a clutch part |54 mounted to ro-r tate and slide longitudinally on shaft 60 (Figs. 1, 9 and 10) Clutch part |54 has a tongue |55 sliding longitudinally of the shaft in a groove |56 in a sleeve |51 rotating on the shaft and in a bearing |58 on the main frame. The sleeve has 'xed thereon a gear |59 for driving the mechanisms of the horizontal turret.

Housed in recesses in gear |59 are one or more springs |60 pressing against a side face of the clutch part |54 for sliding it longitudinally of the shaft to engage its opposite clutch face |6| with'the clutch face |62 on fi/complementary clutch part |63 which is keyed on the main shaft. The slot |53 in the clutch part |54 has a portion |64 (Fig. 9) inclined longitudinally of the main shaft, which portion, in one position, strikes stud |52 on trip lever |5I, thusA shifting the clutch part' downwardly in Fig. 9 and toward the left in Fig. 1, against spring |60, so as to disengage the clutch face, the parts then being in the position shown in Figs. 7 and 9. Slot |53 contains an elevated stop portion |65 (Fig. '1) positioned to engage stud |52, in the disengaged position of the clutch and positively stop the rotation of this clutch part, if not stopped, as normally the case, by a spring'actuated detent hereafter described.

When one of the dogs |48 raises the forward end of lever |5| and lowers its rear end, the abutment or stud |52 is withdrawn from slot |53 and spring |60 slides the clutch part longitudinally into engagement with the clutch part |63 fixed on the shaft, thus driving the gears |59 and 58 and shaft 59, and the turret slide and mechanisms driven thereby.

To prevent any clashing of the clutch teeth, cam slot |53 is provided also with an inclined portion |66 formed on the side face of a rib portion |61 of greater radius than the part |65, so as to strike studv |52 while the stud is withdrawn from slot |53, and assist spring |60 in shifting clutch part |54 into engagement with the mating clutch part. The trip lever is quickly released by its dog, however, and thereafter returned by a spring plunger |68 (Fig. 1) mounted on the frame, so that stud |52 reenters slot |53 for repetition of the cycle. This particular clutch part rotates through one revolution with the main shaft before' being disengaged, such motion being sufficient for an operation of the mechanism controlling the movements of the turret tools; Clutch part |54 is provided also with a 'V-shaped notch |69 (Figs. 9 and 10)V for cooperation with a spring 'actuatedv detent nger l|10 (Fig. 1) to arrest and vposition the clutch and associated parts between actuations thereof. l

The rear cross slide is actuated by the next adjacent carrier |1| (Fig. 3) on: the carrier shaft |04, the carrier being provided with one or more dogs for tripping a lever |12 (Fig. 6), pivotally mounted on the same longitudinal shaft |13 as the above trip lever |5|. These parts haveV substantially the same construction as already described in connection with the carrier and trip lever for the horizontal turret. Lever |12 carries at its' rear end a similar stud |14 (Fig. 6) for coaction inthe same way with a similar clutch part |15, rotatably and slidably mounted on shaft 60. This clutch part is arranged 'for driving engagement with the opposite face of the said clutch part |63 fixed on the shaft and has a splined driving connection with a sleeve |16 rotating on the shaft, the sleeve having xed thereon the said gear 23 for actuating gear |2| and the crossl the trip lever stud to engage and disengage the clutch part, as described above in connection with the corresponding clutch for the horizontal turret snde.

The front cross slide is actuated by a trip dog carrier |80 xed on shaft |04 at a point'still farther toward the left as viewed in Fig. 5, for actuating a corresponding trip lever |8|.

carrier and lever both have substantially the same construction as described above in connecltion with the turret slide and rear cross slide,

'and the trip lever controls, in the same way, a similar clutch part |82 cooperating with aclutch part |83 fixed on the mainshaft. This shiftable Aclutch part is keyed or splined to a sleeve |84 'rotating on themain shaft and in a bearing on the frame, as shown. Keyed on the other end of `the sleeve is the said gear |22 for driving gear '"|20 and the crank ||8 of the front slide. As this V|04 is carrier |85 (Fig. 5) `provided for actuating trip levers |86 and |81 for actuating vertical plungers |88 and |89, respectively, comprising parts of a mechanism for shifting a shipper lever|90 and clutch |9| for reversing and changing the speed of the work spindle which, however, form no part of thewpres'ent invention, and need not be described, v

The next adjacent trip dog carrier |92 is provided for actuating a vertical turret (not shown), when employed onthe machine, but as the same forms no part of the presentinvention, vfurther reference thereto is not require The last trip dog carrier |93 operates a trip lever |94 for shifting a clutch part, such as described above, for driving a cam drum |95 (Figs. 2') employed to control a shipper lever |96 for operating the usual work collet and also an adjustable block and guide device, indicated gen- This yond the bracket. The other brackets are similarly equipped and parts of the casing or housing of the machine, as best shown at 2|5 (Fig.'

l1), carry hooked arms 2|6 arranged to be detachably engaged over either or both ends of the bar 2|4 of each bracket, as an advantageous means of supporting the lower ends o-f such casing portions, which are provided with additional means for supporting the same on the frame adjacent their tops, as by means of a projecting pin 2` 1.

The operation of the various parts of the machine will be apparent from the above description. As the main shaft is rotated by its motor, it drives, through its gear and shaft connections, the cross slide cam shaft |04 which mounts also the various trip dog carriers. The horizontal turret in indexed and rapidly advanced to present one of its tools in preliminary or operating position, by means of the crank on the turret slide. The selector disk assembly is correspondingly indexed to connect with the slide the lead cam co-rresponding to the tool in operating position and through the actuator rod 34 thereby selected, the required, portion of the lead cam contour produces feeding actuation of the tool. The turret slide is then rapidly withdrawn by its crank mechanism forv repetition of the cycle.

At the desired points in the forming of the Work piece, the cross slides are operated in accurately timed relation with the other operations of the machine and inthe same rapid fashion. To this end, the trip dogs are positioned on the carriers on shaft |04 so as to operate the trip levers in timed relation with the operation of the cross slide cams |03 and The trip levers release their respective driven clutch parts for actupation by their springs into instant engagement with the driving. clutch parts, thus actuating cranks I8 and |9 through a half revolution. By means of links ||2 and |I3, the toggle ,levers 84 are quickly straightened to rapidly advance the cross slides to preliminary position, at whichv point the said cams take up the feeding actuation of the cross slides and their tools. By properly positioning the trip* dogs, the cam connecvprovide for operation of the cross slides with a minimum requirement of time and interference Withthe other coordinated operations of the machine.

The various adjustments described are readily accessible and afford complete control over the range and amplitude of movement of the cross slides. By means of the novel construction of the clutch parts actuated by the trip levers, such parts are positively moved by the inclined portions |64 and |66 of their cam grooves |53 (Fig. 9), thus speeding up the operation of the clutches and avoiding any clashing or chattering of the clutch parts against each other. In such actuation of the clutch parts, the trip levers are completely supported by the brackets |99, 205 and 206 and their adjustable abutments, which may be readily removed, however, for access thereto. v

` It will thus be seen that the invention accomplishes its objects, and While it has been herein disclosed by detailed description of'a preferred 1. In an automatic screw machine having aj frame and a work spindle thereon, the combination With `said frame of a pair of tool cross slides movable on opposite sides of said frame, respectively, toward and from said spindle, a lever pivoted on said frame and connected with each slide, operating cam means for each slide, a pair of toggle links pivotally connected with said cam means and said lever, respectively, and having a pivotal knee connection with each other, and means for `operating said cam means and said pairs of toggle levers for actuating said slides.

2. In an automatic screw machine having a frame and a work spindle thereon, the combination with said frame of a pair of tool cross slides oted on said frame and connected with each slide,

cam means for operating each slide, a pair of toggle links pivotally connected with each cam means and lever and having a pivotal knee rconnection with each other, a pair of cranks rotatably mounted on said frame, rods connecting said cranks with said toggle means, respectively, and means for actuating said cam means and cranks.

3. In an automatic screw machine having a frame and a Work spindle thereon, the combination. with said frame of a` pair oi tool cross slides movable on opposite sides of said frame, respectively, toward and from said spindle, a link pivoted to each slide, a-lever pivoted on said frame and pivotally connected to each link, cam means for each slide, a pair of toggle links on each side oi said frame pivotally connected with said cam means and with said lever and having a pivotal knee connection with each other, a pair of cranks rotatable on said frame between said toggle links, rods connecting said cranks with said toggle means, respectively, and means for actuating said cam means and said cranks for moving said slides.

4. In an automatic screw machine, 'a frame,

a notary work spindle thereon, a pair oi tool cross slides movable on opposite sides lof said frame', respectively, transversely of said spindle, a link pivoted to each slide, a lever pivoted 0in-said frame and pivotally connected with each link, cam means for actuating each slide, a pair of toggle links pivotally connected with said cam means and lever of each slide and having a pivotal knee connection with each other, a crank `for each slide rotatable on said frame, rods Vconnecting said cranks with said toggle means, respectively,`

clutch means for operating said cranks, trip means for operating said clutch means, and

mechanism for actuating said cain means and trip leven 6. In an automaticscrew machine, a frame, a tool slide movable on said frame, a shaft on said frame, a carrier on said shaft, a trip dog having `a peripherally adjustable mounting on said carrier, a lever pivoted onsaid frame and provided adjacent one end with trip means for actuation by said dog, mechanism foriactuating said slide comprising a clutch, spring means for moving said .clutch to active position, meansarranged on the opposite end of said lever for engagingand actuating said clutch against said spring means i in a lateral direction substantially .parallel with the pivotalaxis of said lever, a bracket removably mounted on said frame, and abutment means s adjustably` mounted on said bracket for lateral s engagement with the clutch actuating end of said lever in opposition to the thrust of said `spring v means, for supporting said l'ever against the lat-` eral thrusting action of said spring means,

7. In `an automatic screw machine, a frame, a tool slide Vmovable on said frame, a` shafton said frame, a carrier on said shaft, a trip dog having a peripherally adjustable mounting on said carrier,` a lever pivoted on said frame and provided adjacent one end with trip means for actuation by said dog, mechanismfor operating said slide comprisinga spring actuated clutch, means on the opposite end of said lever `for moving said clutch against said spring actuation thereof, spring actuated means on said frame for moving said lever into clutch engaging position, and a removable bracket on said frame pro-` vided with adjustable means for engagement with said lever to support the same against the action of said spring means.

8. In an automatic screw machine, a frame, a tool slide movable on said frame, a shaft on said frame, a carrier on said shaft, a trip dog having a peripherally adjustable mounting on said carrier, a lever pivoted on said frame and provided adjacent one end with trip'l means for actuation by said dog, mechanism forgoperating said slide comprising. a clutch,l spring means for moving said clutch, means on the opposite end of said lever for moving said clutch in opposisaid cam trackfor positively moving said driven j part into clutching engagement and for subsequently` moving said abutment to position for engaging and moving another portion of said cam track for positively moving said driven part out of engagement with said driving clutch part, for effecting the movements of said tool. Y

10. In an automatic tool machine, a tool movable toward and from the work, mechanism for moving said tool comprising a driving clutch part and a driven clutch part movable into` and out of engagement with said driving part, spring means `for moving said driven `part into engage-- ment, said driven part being formed with oppositely inclined cam faces, an abutment for cooperation 'with said cam faces, and means actuated by said mechanism independently cf said cam faces for moving said abutmenttoposition for engaging and moving one of said c am faces to positively move said driven part into` clutching engagement and for subsequently moving said follower to position for engaging and moving the other of said cam faces for positively movl i ing said driven part out of clutching engagement against the action of said `spring means, for effecting the movements of said tool.

11. In an automatic tool machine, a tool movs able toward and from the work, mechanism for moving said tool comprising rotary driving and driven clutch parts, said driven part being movable into and out of engagement withsaid driving part, spring means for moving said driven part into engagement, said driven part being formed with oppositely inclined cam faces .spaced t from each othercircumferentially` of said driven part and located at different radial distances from the rotary axis thereof, an abutment for cooperation with said cam faces, resilient means for movi ing saidabutment to position for cooperation with one ofsaid cam faces `during rotation of said driven part topositively move said part out of clutching engagement against the action of said s spring means, and means actuated by said mechanism for subsequently moving said abutment `to position for cooperation with the other ofsaid` cam faces for assisting said spring means in mov-s ing said part into clutching engagement, for ef- Y being movable into and out of engagement with" tion to said spring actuation thereof, spring i f able toward and from the ,work,. mechanism for `moving said tool comprising rotatable `driving and driven clutch parts, said driven part being track provided with portions for moving the same in opposite directions into and out of` engagement with said driving clutch part, anabutment for cooperation with said cam track,land means actuated by said` mechanism independently of said cam track for moving said abutment to position for engaging and actuating one portion of spaced from each other circumferentiallyof said fecting the movements of'said tool.`

12. In an automatic screw machine having a tool movable toward and from the work, mechanism for `moving said tool comprising rotary driving and driven clutch parts, said driven part `said driving part, spring means tending to move said driven partinto engagement,'said drivenpart being formed with oppositely inclined cam faces s driven part and located at different radial distances from the rotary axis thereof, an abutment i for cooperation withsaid cam faces, means actuated by said mechanism for moving said abutment radially to position for cooperation with i `one of said cam faces during rotation of `said formed with a circumferentally extending cam i driven part to positively move said part out of engagement with said driving part, and means actuated by said mechanism `for subsequently" moving said a abutment radially to position for` cooperation with the` other of said cam faces for ,i positively moving said drivenpart into engageof said tool.

ment withsaid driving part to effect movement FREDERICK G. srLvA. i WRAY s.` SEYMOUR. s 

